Exploration of the mechanism of enhanced CMAS corrosion resistance at 1500?C for multicomponent (Er0.25Tm0.25Yb0.25Lu0.25)2Si2O7 disilicate

(Er0.25Tm0.25Yb0.25Lu0.25)(2)Si2O7 with excellent CMAS corrosion resistance has been designed for the application of environmental barrier coating. The mechanisms governing the enhancement was disclosed through experi-mental investigations of the bulk sample corroded by highly corrosive CMAS melts at 1500 ? for 4 and 50 h. The results demonstrate the synergistic effects of multi rare earth species for the improved CMAS resistance of RE-disilicates. Inert elements (Lu/Yb) benefit the maintaining of phase stability of the disilicate; and simulta-neously, active elements (Er/Tm) promote the precipitation of precipitated phase and reduce the corrosion ac-tivity by promptly change the composition of CMAS.